In general, diamine is used as a monomer for a condensation or addition polymerization of polyimide, polyamide, polyurea, etc. Since the obtained polymers have ring structures as main structure in the molecules, they have many characteristics in which they are large in mechanical strengths such as tensile strength and bending strength and in which they are superior in thermal stability such as thermal decomposition temperature and thermal deformation temperature. Thus, they are regarded as high-performance engineering plastics.
Regarding these resins, there have been made various applications such as engineering plastics, heat-resistant coating materials, electronic materials, electronic component materials, and optical materials. In particular, when the uses to semiconductors and optical members are assumed, low dielectric constant property and high transparency are required as a result of an increasing need for high-speed processing use and high-frequency use together with the development of communication equipment. Being low in thermal expansion is also said to be an important point. As a means for providing such low dielectric constant and a means for providing such high transparency, fluorine-containing polymers, which lower electron density, are actively studied. For example, Non-patent Publication 1 has a description of lowering a fluorine-containing polyimide in dielectric constant, and Non-patent publication 2, which is cited therein, discloses that dielectric constant becomes low by increasing the fluorine content.
Since fluorine-containing compounds are used in a wide applied field by centering on the leading-edge filed, since they have characteristics, such as low water absorption, heat resistance, weather resistance, corrosion resistance, transparency, low refractive index property and low dielectric property, resulting from possessing fluorine atom. They are applied mainly in the coating field at each wavelength.
Hitherto, there have been known methods of introducing a long-chain perfluoroalkyl and of replacing hydrogen of aromatic ring with fluorine, as a method of increasing the fluorine content in the fluorine-containing polymer. In many cases, however, these methods lower adhesion property of the polymer to silicon substrate. For example, although Patent Publication 3 discloses an invention of an optical waveguide constituted by a fluorine-containing polyimide, it discloses that there is a need of forming an adhesion layer for improving adhesion with substrate. Thus, there has been a demand for a fluorine-containing polymer exhibiting characteristics such as low dielectric property and high transparency, while maintaining high fluorine content and retaining adhesion property.    Non-patent Publication 1: “The Latest Polyimide-Basic and Application-” edited by Japan Polyimide Study Group, P 269-283 (2002)    Non-patent Publication 2: “Nitto Giho”, 28(2), 49, (1990)    Patent Publication 1: Japanese Patent Laid-open Publication No. 2001-100055